Build a canal and move water from the flooded east to the parched southwest.

Build a freshewatercanal, with locks on each end from Texas to California.
Make it wide enough for ships. Tunnel under the Rockies.
It will also need feeder canals from the most flooded areas and rivers.
It will serve as a boarder protection, Replacement for the panama canal, create jobs and Solve some of the flooding and water shortage problems.
The exact path and planning should be done by experts in the fields of environment, and engineering, and all others as needed. This could be a generational project providing jobs and promoting commerce on water instead of rail and road.